It was painful to watch Trump apologists fan out in the media to defend the president over the weekend. They have a persuasive argument to make against the obstruction probe reportedly being pursued by special counsel Robert Mueller. But it cannot be made without discussing impeachment.

It seems Team Trump has calculated that the word “impeachment” must be resisted — that utterances of it would cross a psychological barrier, normalize public consideration of it, begin to create the political conditions in which it could actually happen.

It is a bad strategic call. It is like telling your advocates: “Go explain two-plus-two. But whatever you do, don’t mention the word ‘four.’”

Here is how this works.

There is no legal obstruction case against President Trump. As we have repeatedly explained, obstruction requires prosecutors to prove beyond a reasonable doubt that a public official acted corruptly in endeavoring to influence or interfere with an investigation. To establish the corrupt mental state, prosecutors must prove that the official knew what he was doing was against the law.

The president’s actions here, no matter how much one might judge them ham-handed or inappropriate, were not against the law. A president has prosecutorial discretion: He may lawfully shut down an investigation, to say nothing of merely influencing it. And the intelligence services exist to serve the president: He may lawfully terminate any intelligence-collection effort he chooses to.

In point of fact, Trump did not shut down the investigation of Michael Flynn or the counterintelligence probe of Russia’s meddling in the 2016 election. Since he had the authority to bring these investigations to a screeching halt, he cannot have acted corruptly by taking lesser lawful action. Period.

The claim that Trump may be guilty of a prosecutable obstruction crime is premised on a legal error – namely, that the FBI and the Justice Department are a separate branch of government, independent of the executive. In fact, they are subordinate to the president. The power they exercise, as inferior officers, is the president’s power. It does not matter whether an FBI director finds it troubling that a president makes suggestions to him about how a case should be handled. The president gets to do that. If the FBI director finds that intolerable, he can resign. The director’s comfort level is constitutionally irrelevant.

Prosecutorial discretion is part of a continuum of executive police powers that includes the ultimate interference in law-enforcement: the pardon power. No matter how offended we are when a president pardons (or commutes the sentences of) serious criminals, the matter is unreviewable by the courts. The president may not be prosecuted for obstruction of justice over it, even though it seems like a profound obstruction of justice, because the president has the indisputable authority to take the action.

Prosecutorial discretion is no different. It is simply the beginning of the process rather than the end – i.e., the decision not to investigate a potential crime, rather than, by pardoning it, to create the constructive legal reality that the crime never happened. The powers of prosecutorial discretion and pardon are two sides of the same coin.

But now we come to the place where Team Trump goes too far. Based on this constitutional reality of supreme presidential authority over the exercise of executive powers, they jump to the conclusion that the president cannot be investigated or otherwise held accountable for abuses of executive power.

This is self-evidently not true. In our constitutional system, the framers made impeachment, not prosecution, the check on abuse of executive power. If a president decided to release every convict in the federal prison system under his pardon power, he could do that. He could not be prosecuted for it because the Constitution permits it. Congress, however, could impeach and remove him because such an abuse of his unquestioned power would be a massive betrayal of the president’s public trust.

What is true of the pardon power is true of other exercises of prosecutorial discretion – e.g., the decisions whether to pursue an investigation or file an indictment in a worthy case.

Obviously, a president can be impeached over obstructing the administration of law-enforcement and judicial proceedings. As I’ve pointed out before, the Nixon impeachment articles prominently included interference with FBI investigations (among other obstructive conduct). Both Clinton impeachment articles involved obstruction of justice.

Consequently, the arguments from Team Trump that the president cannot commit obstruction are wrong. Worse than wrong, they are extremely counterproductive. They intimate that the president’s position is that, because he may not be prosecuted in a criminal court, he is above the law. It is as if he were claiming he cannot be held accountable for abuses of executive power.

That is an obnoxious suggestion. The natural effect of making an argument that offends people is that it vastly increases their incentive to cut you down to size. It makes them much more open to the idea that the president should be aggressively investigated by an independent prosecutor. They will not abide Team Trump’s contention that the president cannot be prosecuted, because what they think they hear Team Trump saying is that he is immune from all accountability – which he most emphatically is not.

In our system, the independent check on the president is Congress, not a prosecutor. The process for reining in executive abuse is impeachment, not indictment.

Trump’s advocates need not be afraid of this. It is constitutional reality, so there’s no sense hiding from it. As a practical matter, moreover, Trump has clearly not committed impeachable offenses, and he is obviously not going to be impeached and removed from office. There is therefore no reason to be paralyzed by the I-word.

In an impeachment case, Congress would not have to find the president’s actions in an individual case were corrupt beyond a reasonable doubt. Impeachable offenses – high crimes and misdemeanors – need not be indictable offenses. They need to be profound abuses of power that demonstrate unfitness for the president’s public trust.

Thus, the very different question in an impeachment case would be: Has the president’s intrusion of political considerations into law-enforcement decisions so undermined the integrity of the criminal-justice system, so threatened the rule of law on which our society depends, that he has demonstrated himself unfit for his constitutional duty to take care that the laws be faithfully executed?

President Trump expressed hope that the FBI would drop the Flynn investigation. He later removed the FBI director over his exasperation with the director’s failure to tell the public Trump was not suspected of collusion in Russia’s election meddling. These actions, in addition to not being obstruction, are woefully short of the type of abuse of power that would justify impeaching and removing a president.

Trump’s actions do not approach the abuse-of-power predicate for high crimes and misdemeanors.

This is not a systematic threat against the rule of law. Even the Flynn investigation and the Russia probe are going forward. So, Trump has not even undermined the administration of law in the two matters at issue – and the latter one is not even a law-enforcement matter, it’s an intelligence-gathering exercise. It would thus be ludicrous to argue that he has undermined the system of justice to such a degree that impeachment is warranted.

This is a very straightforward argument. First, Trump may not be prosecuted for obstructing investigations because he did not act corruptly – he had the authority to take the actions he did; and these actions, even if one finds them inappropriate, were not unreasonable. Second, Trump may not be impeached because his actions, even if one finds them inappropriate, do not approach the abuse-of-power predicate for high crimes and misdemeanors.

But it is not enough to make the first part of the argument and pretend that the second need not be addressed. If Team Trump is to defend the president effectively, its spokesmen must concede that he is not above the law, and that the Constitution holds him accountable. The point is not that impeachment should not be mentioned; it is that he has not done anything impeachable.